/*
 * Copyright (C) 2012 Roman Yakovenko <b179a9@gmail.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package com.b17.net.protocol;

import com.b17.crypto.core.Utils;
import com.b17.net.exception.ProtocolFailedException;
import com.b17.net.listener.ClientPacketListener;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Arrays;

/**
 * Created by b17
 * 3/4/12 10:47 AM
 */

public class FragmentationWriter {

    public static final int FRAGMENT_SIZE = 32768;
    private OutputStream outputStream;
    private InputStream inputStream;

    private ClientPacketListener packetListener = null;

    public static final int ACK_SUCCESS = 1;
    public static final int ACK_FAILED = 0;

    public FragmentationWriter(OutputStream outputStream, InputStream inputStream) {
        this.outputStream = outputStream;
        this.inputStream = inputStream;
    }

    public void setPacketListener(ClientPacketListener packetListener) {
        this.packetListener = packetListener;
    }

    public void send(byte[] data) throws IOException, InterruptedException, ProtocolFailedException {
        int fragments = (int) Math.ceil((double) data.length / FRAGMENT_SIZE);
        outputStream.write(Utils.toBytes(fragments));

        int ack = inputStream.read();

        if (ack == ACK_FAILED) {
            throw new ProtocolFailedException("Initial ACK failed.");
        }

        for (int i = 0; i < fragments; i++) {
            int start = i * FRAGMENT_SIZE;
            int end = (i + 1) * FRAGMENT_SIZE;
            byte[] bytes = Arrays.copyOfRange(data, start, Math.min(end, data.length));
            outputStream.write(bytes);
            ack = inputStream.read();
            if (ack == ACK_FAILED) {
                throw new ProtocolFailedException("Fragment ACK failed.");
            }

            if (null != packetListener) {
                packetListener.onPercentDone((int) ((double) i / fragments * 100D));
            }
        }
    }
}
